How should liver hypertrophy be stimulated? A comparison of upfront associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) and portal vein embolization (PVE) with rescue possibility

Efficacy and perioperative safety of different future liver remnant modulation techniques: a systematic review and network meta-analysis

BACKGROUND

In daily clinical practice, different future liver remnant (FLR) modulation techniques are increasingly used to allow a liver resection in patients with insufficient FLR volume. This systematic review and network meta-analysis aims to compare the efficacy and perioperative safety of portal vein ligation (PVL), portal vein embolization (PVE), liver venous deprivation (LVD) and associating liver partition and portal vein ligation for staged hepatectomy (ALPPS).

METHODS

A literature search for studies comparing liver resections following different FLR modulation techniques was performed in MEDLINE, Embase and Cochrane Central, and pairwise and network meta-analyses were conducted.

RESULTS

Overall, 23 studies comprising 1557 patients were included. LVD achieved the greatest increase in FLR (17.32 %, 95% CI 2.49-32.15), while ALPPS was most effective in preventing dropout before the completion hepatectomy (OR 0.29, 95% CI 0.15-0.55). PVL tended to be associated with a longer time to completion hepatectomy (MD 5.78 days, 95% CI -0.67-12.23). Liver failure occurred less frequently after LVD, compared to PVE (OR 0.35, 95% CI 0.14-0.87) and ALPPS (OR 0.28, 95% CI 0.09-0.85).

DISCUSSION

ALPPS and LVD seem superior to PVE and PVL in terms of achieved FLR increase and subsequent treatment completion. LVD was associated with lower rates of post hepatectomy liver failure, compared to both PVE and ALPPS. A summary of the protocol has been prospectively registered in the PROSPERO database (CRD42022321474).

Portal Vein Pressure Estimation and Portal Hypertension Discrimination Based on Subharmonic Scattering of Ultrasound Contrast Agent Microbubbles

OBJECTIVE

The acquisition of real-time portal vein pressure (PVP) is important for portal hypertension (PH) discrimination to monitor disease progress and select treatment options. To date, the PVP evaluation approaches are either invasive or noninvasive but with less stability and sensitivity.

METHODS

We customized an open ultrasound scanner to explore in vitro and in vivo the ultrasound contrast agent SonoVue microbubbles' subharmonic characteristics with acoustic pressure and local ambient pressure, and obtained promising results of PVP measurements in canine models with induced PH by ligation or embolization of portal vein.

RESULTS

In in vitro experiments, the highest correlations between the subharmonic amplitude of SonoVue microbubbles and ambient pressure were observed at acoustic pressures of 523 kPa and 563 kPa (r = -0.993, -0.993, P<0.05, respectively). The correlation coefficients between absolute subharmonic amplitudes and PVP (10.7-35.4 mmHg) were the highest among existing studies using microbubbles as pressure sensors (r values ranged from -0.819 to -0.918). The PH (>16 mmHg) diagnostic capacity also achieved a high level (563 kPa, sensitivity = 93.3%, specificity = 91.7%, accuracy = 92.6%).

CONCLUSION

This study proposes a promising measurement for PVP with the highest accuracy, sensitivity, and specificity in an in vivo model compared to existing studies. Future investigations are planned to assess the feasibility of this technique in clinical practice.

SIGNIFICANCE

This is the first study that comprehensively investigates the role of the subharmonic scattering signals from SonoVue microbubbles in evaluating PVP in vivo. It represents a promising alternative to invasive measurements for portal pressure.

Extended Ligation of the Hepatic Vein May Yield a Similar Effect to Liver Venous Deprivation in a Rat Model

AIMS

To validate the hypothesis that hepatic vein ligation (HVL) alone may produce similar results to liver venous deprivation (LVD or HVL + portal vein ligation [PVL]).

METHODS

Rats were assigned to five groups, namely, the control group; the R group in which the right median hepatic vein (RMHV) was ligated; the M group in which the middle median hepatic vein (MMHV) was ligated; the RM group in which both the RMHV and MMHV were ligated (R + MMHVL, extended ligation of the hepatic veins); and the LVD group in which both the right median portal vein and the RMHV were ligated. The liver hypertrophy effect and liver enzymes were determined. Methylene blue staining and retrograde pressurized perfusion assays were performed to investigate the hemodynamic changes.

RESULTS

The RM and LVD groups exhibited similar significant hypertrophy in the future liver remnants when compared to that of the control group, and almost no additional hypertrophy effect was observed in the R and M groups. There was a remarkable elevation in serum transaminase levels in both groups. The methylene blue staining experiment indicated that pressure-dependent collaterals formed between the contiguous drainage areas, and the R + MMHVL procedure blocked the outflow of the right median lobe.

CONCLUSION

Extended ligation of the hepatic vein (R + MMHVL) resulted in a similar hypertrophy effect and hepatic damage to those of LVD (HVL + PVL) treatment in a rat model, and intrahepatic venovenous collaterals play key roles.

Extreme hepatectomy with modified ALPPS in a rat model: gradual portal vein restriction associated with hepatic artery restriction

BACKGROUND & AIM

Associating liver partition and portal vein ligation (PVL) for staged hepatectomy (ALPPS) is a creative strategy for enlarging the future liver remnant (FLR) and increasing the tumor resectability rate. However, the indications for ALPPS must have a certain limit when the FLR is too small. We aimed to establish a modified ALPPS model with more widen applicability in rats.

METHODS

An extreme ALPPS model was established in rodents with only a 6.5% FLR. The portal vein (PV) was subjected to restriction to different degrees, then the portal vein pressure (PVP) was measured. Then, different modifications of ALPPS, including hepatic artery restriction (HAR), gradual portal vein restriction (GPVR), and GPVR-associated HAR (HAR+GPVR), were applied in the extreme ALPPS models.

RESULTS

PVL or PVR provoked an immediate increase in the PVP. The PVP in the PVR -1.28 mm, PVR -0.81 mm, PVR -0.63 mm, and PVL groups was 11.05±1.57 cmH2O, 16.18±1.92 cmH2O, 20.66±1.99 cmH2O, and 24.10±3.33 cmH2O, respectively, and the corresponding 3-day survival rate was 100%, 90.09%, 36.33% and 0, respectively. Then, in the extreme ALPPS model, the growth ratio of the FLR in the control, HAR, GPVR, and HAR+GPVR groups was 0.43±0.21, 0.50±0.16, 4.80±0.86, and 7.40±2.56, and as a consequence, the corresponding 30-day survival rate was 9.09%, 15.38%, 84.61% and 92.90%, respectively.

CONCLUSION

ALPPS itself has a limit, and high PVP after PVL contributes to postoperative death in the extreme ALPPS model. Furthermore, a modified method for extreme ALPPS is proposed, i.e., GPVR+HAR in place of PVL, which significantly improves the survival rate of extreme hepatectomy in rat models.

Establishment of a Rat Model of Liver Venous Deprivation: Simultaneous Portal and Hepatic Vein Ligation

BACKGROUND AND AIMS

The aim was to establish a liver venous deprivation (LVD) model in rats, compare hepatic hypertrophy between LVD and associated liver partition and portal vein ligation for staged hepatectomy (ALPPS), and explore the underlying mechanisms.

METHODS

The LVD or extended-LVD (e-LVD) group received portal vein ligation (PVL) combined with hepatic vein ligation (HVL). The ALPPS or e-ALPPS group received PVL plus parenchyma ligation. Liver regeneration was assessed by measuring the liver weight and performing pathological analysis. Liver functions and the sphingosine kinase 1 (SPHK1)/sphingosine-1-phosphate (S1P)/sphingosine-1-phosphate receptor 1 (S1PR1) pathway were also investigated.

RESULTS

All future liver remnants (FLRs) in the ALPPS, e-ALPPS, LVD, and e-LVD groups exhibited significant hypertrophy compared with the control group. The LVD and e-LVD procedures induced similar liver hypertrophy than that in the corresponding ALPPS groups. Furthermore, the LVD and e-LVD methods led to obvious cytolysis in the venous-deprived lobes as well as a noticeable increase in serum transaminase levels, while no necrosis was observed in the ALPPS and e-ALPPS groups. SPHK1/S1P/S1PR1 pathway were distinctly activated after operation, especially in congestive/ischemic livers.

CONCLUSIONS

We describe the first rat model of LVD and e-LVD with simultaneously associated HVL and PVL. Compared with the ALPPS technique, the LVD or e-LVD procedure had a comparable overall effect on the hypertrophy response and a stronger effect on liver function. The SPHK1/S1P/S1PR1 pathway was involved in the LVD- or ALPPS-induced liver remodeling.

Efficacy and safety of different options for liver regeneration of future liver remnant in patients with liver malignancies: a systematic review and network meta-analysis

BACKGROUND

Several treatments induce liver hypertrophy for patients with liver malignancies but insufficient future liver remnant (FLR). Herein, the aim of this study is to compare the efficacy and safety of existing surgical techniques using network meta-analysis (NMA).

METHODS

We searched PubMed, Web of Science, and Cochrane Library from databases for abstracts and full-text articles published from database inception through Feb 2022. The primary outcome was the efficacy of different procedures, including standardized FLR (sFLR) increase, time to hepatectomy, resection rate, and R0 resection margin. The secondary outcome was the safety of different treatments, including the rate of Clavien-Dindo≥3a and 90-day mortality.

RESULTS

Twenty-seven studies, including three randomized controlled trials (RCTs), three prospective trials (PTs), and twenty-one retrospective trials (RTs), and a total number of 2075 patients were recruited in this study. NMA demonstrated that the Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) had much higher sFLR increase when compared to portal vein embolization (PVE) (55.25%, 95% CI 45.27-65.24%), or liver venous deprivation(LVD) (43.26%, 95% CI 22.05-64.47%), or two-stage hepatectomy (TSH) (30.53%, 95% CI 16.84-44.21%), or portal vein ligation (PVL) (58.42%, 95% CI 37.62-79.23%). ALPPS showed significantly shorter time to hepatectomy when compared to PVE (-32.79d, 95% CI -42.92-22.66), or LVD (-34.02d, 95% CI -47.85-20.20), or TSH (-22.85d, 95% CI -30.97-14.72), or PVL (-43.37d, 95% CI -64.11-22.62); ALPPS was considered as the highest resection rate when compared to TSH (OR=6.09; 95% CI 2.76-13.41), or PVL (OR =3.52; 95% CI 1.16-10.72), or PVE (OR =4.12; 95% CI 2.19-7.77). ALPPS had comparable resection rate with LVD (OR =2.20; 95% CI 0.83-5.86). There was no significant difference between them when considering the R0 marge rate. ALPPS had a higher Clavien-Dindo≥3a complication rate and 90-day mortality compared to other treatments, although there were no significant differences between different procedures.

CONCLUSIONS

ALPPS demonstrated a higher regeneration rate, shorter time to hepatectomy, and higher resection rate than PVL, PVE, or TSH. There was no significant difference between them when considering the R0 marge rate. However, ALPPS developed the trend of higher Clavien-Dindo≥3a complication rate and 90-day mortality compared to other treatments.

Safety and efficacy of right portal vein embolization in patients with prior left lateral liver resection

BACKGROUND

In patients with bilobar metastatic liver disease, surgical clearance of both liver lobes may be achieved through multiple-stage liver resections. For patients with extensive disease, a major two-staged hepatectomy consisting of resection of liver segments II and III before right-sided portal vein embolization (PVE) and resection of segments V-VIII may be performed, leaving only segments IV ± I as the liver remnant.

PURPOSE

To describe the outcome following right-sided PVE after prior complete resection of liver segments II and III.

MATERIAL AND METHODS

In this retrospective study, 15 patients (mean age = 60.4 ± 9.3 years) with liver metastases from colorectal cancer (n = 14) and uveal melanoma (n = 1) who were scheduled to undergo a major two-stage hepatectomy, were included. Total liver volume (TLV) and volume of the future liver remnant (FLR) were measured on pre- and postinterventional computed tomography (CT) scans, and standardized FLR volumes (ratio FLR/TLV) were calculated. Patient data were retrospectively analyzed regarding peri- and postinterventional complications, with special emphasis on liver function tests.

RESULTS

The mean standardized post-PVE FLR volume was 26.9% ± 6.4% and no patient developed hepatic insufficiency after the PVE. Based on FLR hypertrophy and liver function tests, all but one patient were considered eligible for the subsequent right-sided hepatectomy. However, due to local tumor progression, only 9/15 patients eventually proceeded to the second stage of surgery.  .

CONCLUSION

Right-sided PVE was safe and efficacious in this cohort of patients who had previously undergone a complete resection of liver segments II and III as part of a major staged hepatectomy pathway leaving only segments IV(±I) as the FLR. .

Portal Vein Embolization Using N-Butyl Cyanoacrylate-Glue: What Impact Does a Central Vascular Plug Have?

Purpose

To examine if the addition of a central vascular plug (CVP) to portal vein embolization (PVE) with N-butyl cyanoacrylate-glue (NBCA) increases future liver remnant (FLR) growth.

Material and Methods

This is a single-center retrospective study of 115 consecutive patients with colorectal liver metastases undergoing PVE in 2013–2019. All patients were embolized with NBCA as the main embolic agent. In 2017–2019 NBCA was combined with a CVP in the central part of the right portal vein. Growth of the FLR and standardized FLR (sFLR) including degree of hypertrophy (DH) and kinetic growth rate (KGR) were analyzed, as well as procedure data such as use of cone-beam CT (CBCT), dose area product (DAP), fluoroscopy time and contrast dose.

Results

A total of 40 patients (35%) underwent PVE with a combination of CVP and NBCA. The DH was higher in these patients after 4 weeks, mean 13.6% (SD 7.8) vs. 10.5% (SD 6.4; p = 0.022), verified in multivariate analysis (coefficient 4.1, p = 0.015). A CVP did not significantly increase the resection rate (90% vs 82%, p = 0.4). Cone beam CT was used in 65 patients (57%). Use of CBCT did not affect FLR growth, and fluoroscopy time and contrast doses were not different in patients having a CBCT or not. Slightly lower DAP (median 3375 vs. 4499 cGy*cm²; p = 0.09) was seen in procedures where CBCT was used.

Conclusion

A CVP in addition to NBCA embolization was associated with increased growth of the FLR compared to NBCA alone.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00270-021-03014-w.